The Berkeley Police Department will not carry out a criminal investigation into the balcony collapse that killed six students and injured seven others.

The City of Berkeley has confirmed that no person or entity is being investigated, and that city officials have closed their investigation.

Niccolai Schuster (right)Olivia BurkeEimear WalshLorcán MillerAshley DonohoeEoghan CulliganBerkeley Mayor Tom Bates (L) hugs Philip Grant, Consul General of Ireland to the Western United States, following a wreath-laying ceremony at the scene of a 4th-story apartment building balcony collapse in BerkeleyThe remains of the damaged balcony are removed from the 4th-story apartment building in Berkeley. Photo: ReutersWorkmen examine the damage at the scene of the balcony collapse in Berkeley, CaliforniaInjured student Jack HalpinPolice hold up sheets as medical staff take away the bodies of the dead students at the Library Gardens apartment complex in Berkeley.Stunned onlookers at the scene of the tragedyVisitors lay flowers on a makeshift memorial near the scene of a 4th-story apartment building balcony collapse in Berkeley, CaliforniaConor FlynnJack Halpin (left)Hannah Waters (right) was also injuredNiall Murray

The City of Berkeley released the results of its investigation into the incident yesterday and found evidence of "severe" and "extensive" dry rot in the balcony.

The authority said that the number of people on the balcony at the time was not a factor in its collapse.

As of now, civil actions are the only recourse available to those involved in the tragedy.

Despite the confirmation that no criminal investigation would be carried out, the city’s district attorney office said it was still considering an investigation into the accident.

Stressing that no formal inquiry had been launched, the district attorney’s office in Berkeley said it was currently exploring whether any crime had been committed.

As funerals took place in Dublin for two more victims of the balcony collapse, father of Niccolai Schuster, buried today, urged US investigators to leave no stone unturned.

“This cannot happen again,” he said.

The Mayor of the City of Berkeley Tom Bates said he doesn't know who could be blamed for the deaths of the six young students.

“I don’t know [who will be blamed for the deaths] but I’m sure there’s going to be lawsuits, a lot of people looking at that… contractors, the owners… the contractor and the owner, does the city have any liability, I hope not because we did inspect according to the building codes," he said.

“I’m sure the lawsuits will name everyone they can possibly think of. We know that that’s going to happen. We’ve already been notified that there’s people contemplating lawsuits or in the process of filing lawsuits.

“It’s hard to put the blame on anyone, I’m not in a position to do that," he told Newstalk this morning.

“You have to realise there was a contractor who built this, who put in the wood and the surrounding structure, they’ll be the first people that people will look it. And then there’s the architect, the general contractor, the owner. It’s going t take a while to get around all of this.

“And probably, I’m just speculating, but there could be more than one person or company that will deemed to be responsible,“ he added.

The Library Gardens apartment complex was only commissioned in 2007 and the timber beams should have been able to support a balcony weight of almost two tonnes.

However, it failed at 12.41am last Tuesday, throwing six students, five Irish and one Irish-American, to their deaths.

Seven other students were badly injured.

The report, compiled by City of Berkeley engineers under Housing Safety director Alex Roshal, confirmed that: "The deck joist ends protruding from the exterior wall appeared to be severely dry rotted."

However, the full report into the horrific accident at 2020 Kittredge Street will not be completed for several months.

The City of Berkeley has confirmed that, in light of the findings and the scale of the tragedy, new regulations will come into force.

"Based on their observations, city staff will recommend that the city council adopt new and modified regulations to enhance the safety of all current and future buildings in Berkeley," an official said.

"The changes would make new balconies and other sealed areas exposed to weather subject to stricter requirements on materials, inspection and ventilation."

The investigation is focused on why eight-year-old timber beams rotted so badly.

Engineers are examining the waterproofing of the joists.

Speaking to Newstalk's Breakfast, Mayor Bates described new building measures that will be adhered to in the city.

“What the report says to me first or all is we’re going to go back and inspect every balcony to avoid similar situations," he said.

“The second thing then is that we will have periodic review that we will also execute so that every five years, all the buildings are inspected.

“It’s also true that most new buildings in Berkeley don’t have balconies… or if they do, they’re only one foot or something where you couldn’t go out on it, but it’d be used for plants," he continued.

“So the main thing is, what seems to me, is the things we’re suggesting in a building code are more important… to ensure ventilation to any kind of structure that’s going to be supportive so we can get air in and so that there won’t be a chance to gain moisture and dry rot.

“That seems to me to be a very important change in our building code and in our inspection.”

However, Mayor Bates said he doesn't know who could be blamed for the deaths of the six young students.

“I don’t know [who will be blamed for the deaths] but I’m sure there’s going to be lawsuits, a lot of people looking at that… contractors, the owners… the contractor and the owner, does the city have any liability, I hope not because we did inspect according to the building codes," he said.

“I’m sure the lawsuits will name everyone they can possibly think of. We know that that’s going to happen. We’ve already been notified that there’s people contemplating lawsuits or in the process of filing lawsuits.

“It’s hard to put the blame on anyone, I’m not in a position to do that.

“You have to realise there was a contractor who built this, who put in the wood and the surrounding structure, they’ll be the first people that people will look it. And then there’s the architect, the general contractor, the owner. It’s going t take a while to get around all of this.

“And probably, I’m just speculating, but there could be more than one person or company that will deemed to be responsible,“ he added.

The Irish students who died were all from south Dublin - medical students and friends Lorcan Miller and Eimear Walsh; Olivia Burke, who went to school with Eimear; Niccolai Schuster, who was at the same college at Lorcan and Eimear, and his friend from school Eoghan Culligan.

Irish-American Ashley Donohoe, who lived in California and was a cousin of Olivia's, also died.

Seven others were badly injured, with one of them being released from hospital in the US today and others expected to undergo treatment over the coming weeks.